Re: Two ignition keys?
Just a guess here, but since i see a locator on the console, there may be a trolling motor on the boat as well and the prior owner decided that he wanted stuff powered from the troller batteries or a second (house) battery. That requires the helm be disconnected from the ignition switch on the control box and moved to the second switch so it can be used to power the accessories on the helm. Another very "creative" way to keep prying fingers of little "curtain climbers" from fiddling with switches and killing the battery. As for the control box kill switch, that requires only a lanyard with the plastic clip on the end, or any lanyard with a ring on the end. You flip the switch down, slip the ring over the toggle and flip it back up. Why the lanyard is pulled the toggle moves down killing the engine.
Lastly, is it also possible that this boat was fitted with a kicker engine at one time and the second switch and kill switch were for that engine?